[WIP] 1979 Subaru Wagon: Leaf Stack,Zomb,Ioniq 5 1/2 pack

[cajamatt]

I started a build thread for my project on DIYElectriccar and I'm migrating it over to this forum for better community interaction following Bratitude's suggestion.

( Previous thread: https://www.diyelectriccar.com/threads/ ... st-1132030 )

Project introduction from previous thread: (some info now incorrect)

Maybe 4 years ago i learned about EV conversions and have been daydreaming/researching/drooling over other's projects hoping one day I'll get to do one myself. In December 2024 I found a driveable 2013 leaf for sale 5 miles away and took the dive. Extracted the stack and various bits and bobs, sold the 24kwh battery, and brought the stack down to my basement while i researched VCUs and batteries.

Goal: daily driver with some character. I need to be able to make a round trip to local bike trails and ski areas about an hour away. currently those trips use about half of the capacity of my nissan ariya (80kwh). Selectable 4wd is required for deep snow and mud season.

Drivetrain: i dont care much about speed/acceleration so leaf stack was the obvious choice

VCU: I wanted to use the resolve VCU, but leaf batteries are too expensive. Thunderstruck seems the next easiest, but doesn't work with the leaf charger. So Zomb it is!

Batteries: Model S modules seemed like the best value and a great workable form factor, and the Vero2 BMS seems good. However, without reconfiguring the modules I'd be forced into a 70-80 kwh pack to get high enough voltage, which would be tough to fit in the smaller wagon. I considered the rav4 EV's modules made by tesla 10 years ago which run at a higher voltage and are pretty cheap! Also considered BMW PHEV packs. Then i found a Hyundai Ioniq 5 pack for $3100 shipped. Someone has used ioniq 5 modules successfully with an Orion BMS and that was all the encouragement i needed to take the dive. I'm going to use half the pack and sell the remaining modules, which should give me ~40kwh for <30$/kwh!!!

Car: late 70s subaru leone/1600/gl/dl (many names for the same car). basically a wagon version of a brat! only just found out about these cars and it was love at first sight. nothing else checked every box. other options were AMC Eagle SX4, subaru brats, 4wd tercel wagons, and old ford rangers.

Me: early 30s, mechanical engineer in power electronics. i have access to a waterjet and press brake, copper fab shop, and solidworks.


I am now at the stage of applying HV to attempt my first motor spin. Schematic and zombie parameters and questions coming soon!

This project, in addition to being REALLY COOL, will help advance my career, teach me great skills, and reduce my environmental impact. It would never have even been considered without these forums and the wicked smart, generous people here. Even if i don't always say it, my gratitude is always implied. I hope to guide some local friends in conversions of their own once I'm done and have gained the knowledge.

[Bratitude]

You made it
Welcome!

now post your zombie prams and let’s get your motor spinning

[cajamatt]

Reread part of the wiki and tried to run again with the new understanding that udcINV might be read through the precharge so i actually might not be missing any wiring. Also checked my switches and found the on switch was in backwards and the forward/reverse switch just doesn't do anything haha so i connected the forward pin. My parameters are attached, is this an ok way to send them?

momentary on switch pressed and got the follow result several times:
udc 58
opmode pchgfail
lasterr precharge
status udcbelowudcsw
battery voltage: 383
voltage from INV side of contactors: 363 dropping down to 340
udcINV increasing from ~20V - ~50V
no resistance measured across PC resistor
confirmed PC relay is operating

After dinner i'll check the precharge resistor connections. Anything else suspicious?

[tom91]

If it gives you a precharge error and udcbelowudcsw

Guess what you have a precharge error.

Best test all your contactors before using ANY HV.

Negative goes on first, then Precharge. They go off again as the precharge does not complete.

The final one when precharge completes is the Positive Contactor.

You can force it on by settings udcsw to 0. This will complete to contactor sequence regardless of the voltage in the udc spot value. DO NOT SAVE THIS TO FLASH, running this with HV applied will break things.

If your contactors are working as expected and you believe you wired the HV correctly and the 12V into the inverter correctly and the CAN. You should see the values like invudc, tmphs comming from the inverter. if you are not seeing the same reported udc + invudc as you measure going into the inverter I will need a CAN bus log for further diagnosis.

[cajamatt]

The udcsw=0 test worked to close both neg and pos contactors in the right sequence! Thanks for that tip.

I can't get the precharge relay to work. I wired in a contactor in place of the relay and that worked once i figured out the coil has a polarity!

Then i checked things over a few more times and couldn't see anything wrong so i put the HV on and got udc to read 382v! Success!! Pressed the accelerator and nothing. Potnom was reacting to the pedal and nothing else. My forward/reverse "switch" worked. Then the parameters and spot values regions of the inverter interface went blank and didn't come back after a power cycle so i shut it down and disconnected the battery. Cycled 12V and the interface came back. Is there a way to deal with the interface dropping out while running? Is there a known cause for that? Psyched about my progress and now to puzzle over this next speed bump! I'll jump back in after dinner.

[Bratitude]

check and reconnect your wifi
auto connect to your main network can some times cause issues
do you have signal pot selected? i see you have prams tuned for only one pot on the throttle.

your fwd/rev switchs, do you see the spot valves change in the interface?

how do you have the stack wired?

is there any errors showing up in the web interface or dose it just say "run" when precharge has finished?

do you have a stable 12v supply?

[cajamatt]

check and reconnect your wifi
auto connect to your main network can some times cause issues
do you have signal pot selected? i see you have prams tuned for only one pot on the throttle.

your fwd/rev switchs, do you see the spot valves change in the interface?

how do you have the stack wired?

is there any errors showing up in the web interface or dose it just say "run" when precharge has finished?

do you have a stable 12v supply?

yes i have it set to single pot because pot2 was unresponsive in my leaf pedal pot2 on the board works so i think i have a bad sensor in the pedal

yes the forward/reverse spot value change when i change the switch

The stack is wired to the leaf/zomb schematic. I have double checked all the signal wires. The only suspicious wiring i can think of is the CAN wiring. I didn't want to cut off all the lengths of twisted/terminated wire incase i needed it as it is. Many feet of it are bundled in a loop and I'm wondering if that's causing a CAN issue. I'm still working out the do's and don't of CAN, but if this sounds suspicious to you too then i'll lop it off. I scored probably 100ft of twisted shielded pair from work, so that's no longer a limited resource.

no errors! it just says "run"

my 12V supply is a brand new 12V car battery that is still above 12V.

thanks for the questions!!

[tom91]

Please post your params again. Please plot the following: Potnom + udc on Left and Torque on Right.

What are you trying to spin, just the motor with the inverter on top? If you have the leaf gearbox ensure the park lock is disengaged.

[cajamatt]

Parameters from last night attached. I tried to turn down things like rpm limits and max throttles so my motor doesn't dance away, but maybe i went too far? i thought 480 RPM was a reasonable limit for my basement. I took the parking brake off before taking the battery out of my leaf, and i'm able to spin the axle when i stick it back into the gearbox, so i don't think that's the problem.

[cajamatt]

plot attached. i included pot because potnom stayed at 0.

[tom91]

i included pot because potnom stayed at 0.

did you select a direction?

Please post your spot values too

[cajamatt]

here's a pdf of the whole page including the plot. really hoping i missed something silly.

[tom91]

Brake ON, you are now the second person in a 2 weeks to do this.

[cajamatt]

]lAnd here are some photos of the can lengths hanging out of my inverter and pdm connectors I was hesitating to cut off. Could these be causing issues? If they're suspect I can remove them and remake them later on

[Bratitude]

Brake ON, you are now the second person in a 2 weeks to do this.

]lAnd here are some photos of the can lengths hanging out of my inverter and pdm connectors I was hesitating to cut off. Could these be causing issues? If they're suspect I can remove them and remake them later on

why keep all that? You have all the can branches still….


The stack only needs:

12v+
12v -
Can H
Can L
ignition

If you unwrap the harness, very quickly you can separate and clean up to a simple harness.

Add 6pin deutsch dt connector on then end, then wrap it all up. Makes it simple and clean

Also not sure what year stack you have, but that teal line usually is the ignition from the motor harness.

[cajamatt]

I kept the wires because i wasn't sure if there were any i was going to need in the future. Thats crazy you only need 6 wires going to the stack. Very excited to clean up the harness.

Thank you for catching that i wasn't pressing the brake! Sure enough when i press the brake and accelerator i got a spin!! Spent the morning taking the gearbox off and making a new pallet and then after dinner it span first try!!! My girlfriend captured my reaction on video which is pretty funny. The first time i pressed the pedal it span up and then decelerated smoothly. Second time i pressed the pedal it began to judder and i had to switch the system off to get it to stop. I'll play with the throttle/regen/limit settings and do some more research to try to make it accelerate smooth and stable. parameters and plots are attached incase anyone wants to scan for possible fixes.

WOOHOOOOOOOO

[tom91]

Thank you for catching that i wasn't pressing the brake! Sure enough when i press the brake

No your brake switch is the wrong logic. As in when not pressed it outputs 12V.

ll play with the throttle/regen/limit settings

Pointless unless in an actual vehicle.

[cajamatt]

Using the hyundai/kia power relay assembly aka contactor box has one challenge (so far): The relay is not a relay it is actually a FET or something, and my electrical engineer friend and i have a hunch that it requires 800v to operate. I ordered a 400v relay (Panasonic AECN11012) to replace it. It clicks with 12V applied which the previous "relay" did not do! Pics of the mods to install the new relay are below.

relay upright. tidy, but interferes with bus that goes above it.

relay tipped over. had to dremel off some plastic. not as tidy, but fits well and plenty of creepage and clearance distance to buses above. held down with a zip tie and RTV.

Somehow my 12V battery discharged to 4.7v over the course of a week of being unplugged. No idea why that happened and wondering if i can revive it or if it has to be tossed. It was brand new 2 months ago and i didn't notice any dip in voltage in my previous testing.

Still trying to source a Subaru. My contact in connecticut with three of these sandbagged me and doesn't actually want to sell me one. There are 2 in oregon i'm trying to buy, but one of the sellers is on vacation. Simultaneously I have had 2 leads for selling my remaining batteries fall through (one was a scam). Glad i'm in engineering and not purchasing or logistics jeezum!